DIGITALLY CONNECTING CARS to each other and to highway infrastructure promises to drastically reduce collisions and traffic jams. But that wireless vehicular chatter comes at a cost to your privacy: A car that never shuts up may be a lot easier to track.

Researchers at the Universities of Twente in the Netherlands and Ulm in Germany have found that they can use just a few thousands of dollars’ worth of equipment to track a vehicle that’s emitting the so-called “connected vehicle” wireless communications proposed for future vehicle-to-vehicle connections. With only two $550 devices strategically planted at intersections on the University of Twente’s 432-acre campus, they were able to follow unique signatures in cars’ radio communications, predicting which of two campus regions the vehicle was in with 78 percent accuracy, as well as the car’s more precise location on a specific road with 40 percent accuracy. Extrapolating from that proof-of-concept, the researchers believe that the same technique, expanded with a few hundred thousand dollars of hardware, could be used by governments or even amateurs to monitor vehicles over an entire small city.